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My PC restarts during power failure despite UPS

By OneZ
Jan 9, 2011
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  1. Greetings,
    I've moved to another country where electricity is not stable and goes high/low or even disconnect ( power failure ) many times a day. So, i brought an old UPS i have ( discovery ) and connected it to the outlet and connected the PC and the LCD screen to it. Sometimes when the electricity goes high/down the UPS seems can't regulate fast enough or when the electricity disconnect the UPS can't change to battery mode fast enough so the PC restarts.
    I though the problem is from the UPS so i bought a new one ( iXA PRO850 ) which also has a built in AVR with wide input range of 140-285 Vac, wide range of input frequency, output short circuit protection, overload protection and the transfer time is 8ms. I connected the PC and the LCD screen to the new UPS and connected my modem and an external hard to the old one. Surprisingly, when the electricity went high/low or when it disconnected the modem did not reset but my PC restarted which means that the old UPS is still working and the problem is from the PC itself. I use a very god power supply ( Blue Storm - 750 wat ) so any idea what the problem could be ?
    Note 1: When the electricity goes high/low or disconnect the PC doesn't actually restart, it just half turned off, i mean i can still hear the fans rolling but there is nothing on the screen and i have to turn it off then on.
    Note 2: Sometimes when electricity goes high/low or disconnect the PC keeps working normally.
    Thanx in advance.....
  2. EDO219

    EDO219 TS Rookie Posts: 298

    My guess is your power supply in your PC uses active PFC (Power Factor Control) while your uninterruptible power supply is likely rated for a passive PFC.
  3. OneZ

    OneZ TS Enthusiast Topic Starter Posts: 100

    Thanks for your replay.

    Is there anyway to know for certain if your guess is true ? Because it's not written on the power supply if it's active or passive, and on the UPS manual it only says Power Factor = 0.6

    One more thing, this problem never happens when electricity completely disconnects, it only happens when electricity goes high/low. and out of four times when electricity goes high/low the problem happens 1 time, i mean not every time.
  4. OneZ

    OneZ TS Enthusiast Topic Starter Posts: 100

  5. EDO219

    EDO219 TS Rookie Posts: 298

    hm ... Since the PSU is indeed passive, I'm afraid my ability to offer helpful advice is stretched to its limits.

    You might call Mercury regarding your UPS, as it is more likely the issue than your PSU. It sounds as though the fluctuations in power don't always trigger the UPS to kick in as sudden drops in power seem to.
  6. OneZ

    OneZ TS Enthusiast Topic Starter Posts: 100

    Thanx for ur replay.

    I connected my modem and my PC to the new UPS, and when electricity went down, only the PC restarted, the modem didn't.
    Is there any power option in the bios that might have a relevant to this issue ?

    Thanx.....
  7. EDO219

    EDO219 TS Rookie Posts: 298

    I'm not actually aware of any universal option in BIOS's pertaining to an UPS, but I do remember XP having some settings for UPS.

    There is one more thing you might try that I have been reluctant to suggest. lol

    Do you have a power strip that is also a surge protector? If so, perhaps plug it directly into the wall, then the UPS, then your PC into the UPS. Pretty much all UPS have some level of joules they are rated to handle, but the stability of UPS power output for that brief second can still be iffy.
  8. OneZ

    OneZ TS Enthusiast Topic Starter Posts: 100

    Thanx 4 ur replay,

    Unfortunately i don't have such a thing, but i'll try to buy one.

    My mother board is Asus M4A78 Pro which has some integrated power stuff for Longer Life & Higher Efficiency as they said http://www.asus.com/product.aspx?P_ID=EbXqq06yxpJwlABf
    could this be the problem ?
  9. EDO219

    EDO219 TS Rookie Posts: 298

    hm ... The higher efficiency features shouldn't be to blame, but your motherboard does mention "ASUS Anti-Surge Protection".

    Perhaps power surges are to blame as your mobo may be shutting itself off to avoid damage. Yeah, I just found this description of it, "... protects itself by switching-off the unstable power supply." I'm not sure if this feature can be disabled, nor if it would be a good idea to. A surge protector with a decent joule rating should do the trick and if not, then perhaps your other appliances could use the protection.

    Let me know how this turns out! ;D
  10. OneZ

    OneZ TS Enthusiast Topic Starter Posts: 100

    Hey,

    I read about surge protectors and i don't think they would work here, because there is no ground line in the electricity system in this country.

    The ASUS Anti-Surge Protection can't be turned off and I agree with you that this is the problem. Anyway, I've upgraded my Bios to the latest update, and for two days PC never restarted, but today the electricity disconnected for like 6 secs, at firs the UPS switched to Battery successfully and the PC didn't reset but after 2 secs it restarted, yeah very weird.

    Thanks for your help.
  11. EDO219

    EDO219 TS Rookie Posts: 298

    Whoooooaaaaa ... the power outlets don't all have grounds in that country? o_O

    Now that is quite a tricky situation, isn't it. lol ... Well, if you own the residence and are going to be living there a very long time, then you could install a lightning rod and tie the 3rd prong of your outlets into that. This would be a rather drastic solution, though, especially since we're not sure a grounding issue is entirely to blame.

    What if you plug several things (such as lamps) into the UPS so that they might help lessen the power spikes instead of your PC bearing the entire load?
     
  12. Hoshi_Reed

    Hoshi_Reed TS Rookie

    For your outlet problem: Try looking for a line conditioner that has galvanized isolation. These units convert bipolar to tripolar electronically.

    Here in the northeast of Brazil there isn't any ground in the power line, you have to use the rod in ground method and not everyone here can do it. So they offer products like this.

    The only drawback is your monitor/printer/peripherals must go through the same box and your internet must be wireless (as any other cord to a different outlet or even the phoneline can become a passive ground)
  13. OneZ

    OneZ TS Enthusiast Topic Starter Posts: 100

    Thanks all for your replies.

    Well yeah, all the power outlets don't have grounds here :) and I don't own the residence :(
    I already have my modem connected to the UPS and it doesn't restart when PC does!!

    I will search for this conditioner thingy even though I doubt they sell anything like this here.

    By the way, my new UPS is 850VA, can i connect my PC, 23" LCD, modem and external hard disk without over loading it ? I currently only have the PC and the modem connected to it.

    Thanks again.
  14. Hoshi_Reed

    Hoshi_Reed TS Rookie

    What is the rating on your PC PSU? a simple 450? or a better 550 or a whopping 750?
    Your monitor manual should give you the W/VA rating; same with the modem and external HDD.
  15. True liar

    True liar TS Rookie

    I have same problem... my pc restarts on power cut... however the ups work properly on my friends pc. I have MSI G41-P26 motherboard and 450 watt power supply


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